You mentioned the CE line. This sounds similar to the problem that I had
with my 102 ram address decoder circuit. I had to replace the
demultiplexer. If your lowest ram is not responding properly this might
happen?
On Dec 14, 2017 8:18 PM, "Fugu ME100" wrote:
> If your
If your voltages appear stable and in spec I would leave the caps, unless you
see any that have leaked. A white or greenish residue under the cap is
usually a good sign it has leaked. I think the green tint is because it also
etched the copper under the cap.
From: M100
Really appreciate your effort!!!
I'll try to measure the suggested signals and get out my bag of GOOD caps :)
Mauro
Inviato da iPhone
> Il giorno Dec 15, 2017, alle ore 01:55, Fugu ME100 ha
> scritto:
>
> It would be interesting to see if the Address Lines fail at a
It would be interesting to see if the Address Lines fail at a specific address
all the time. Might give a clue as to what is causing the issue. In the old
days it was possible to watch the address lines walk through a count sequence
if you had a bad ROM or RAM. Although this one appears to
Unfortunately the NiCd battery was dead and already replaced twice.
The unit was without power (no cable or battery) for several days since I
struggled to find the NiCd battery.
Considering the age of the unit I think most of the electrolytic capacitors are
dead.
No one suggested to replace
Actually the reset is moving only at power on and when I press the reset
button, otherwise it is stable. I tried to follow the reset signal after the
Reset out of the CPU through couple of buffers but it is consistent and not
cycling.
As LA I only have a Saleae 8 clone, but should do the job.
If you're convinced it's stuck in a loop, removing all power (including
the NiCd) for a time should fix that
On 12/14/17, Mauro Pintus wrote:
> Thank you Fugu and Brian for the feedback.
>
> Yes I tried the beep BASIC test with no luck and also the cold start (the
>
What is the RESET line into the CPU doing during the loops? Is the RESET
stable?
The CPU appears to be RESET, heads to the ROM for data but for some reason
fails to complete and RESETs itself. No activity on the RAM or LCD would
indicate the CPU is not completing the ROM boot. At this
Thank you Fugu and Brian for the feedback.
Yes I tried the beep BASIC test with no luck and also the cold start (the M10
and the M100 are almost identical...).
I made few other measurements trying to replicate what Brian is doing and for
sure the unit is in a loop...
In the linked google
I was just watching a video of 8-Bit Guy on YouTube where he puts
together an "OPL2LPT"... basically a parallel port sound board designed
to work as an AdLib sound card. He'd previously done a video for the
CVX4, a Covox parallel port sound board clone. The OPL2LPT uses the same
Yamaha chip as
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